Holder for an assay device



FIG. 1 is a front view of a holder for an assay device showing my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a right side view thereof, the left side view being a mirror image thereof;

FIG. 4 is a top view thereof; and,

FIG. 5 is a bottom view thereof. 

The ornamental design for a holder for an assay device, as shown and described. 